The use of such piezoceramic components as sensors or actuators, especially in automotive engineering, is due to their high reliability and temporal stability, as well as an adequate thermal stability, while at the same time having relatively large deflections when an electrical voltage is applied. These attributes require one to establish a particular ratio of Zr to Ti in the perovskite structure ABO3 of PZT, corresponding to the so-called morphotropic phase boundary MPB. The piezoelectric properties take on especially advantageous values in the MPB composition range. Furthermore, the functional properties of the lead zirconate titanate ceramic can be adapted very much to the particular application by adding certain additives which go into solid solution in the perovskite structure. In general, one will try not to lower too much the relatively high value of the Curie temperature of around 360° C., responsible for the thermal stability of the piezoelectric properties, as a result of such modifications, which can be accomplished by keeping the concentration of the additive component low.
From publication WO 97/40537 there is known a PZT ceramic which calls for a doping at the A-site of the perovskite structure to improve the properties of the ceramic. A rare earth metal, such as lanthanum or neodymium, is chosen for the A-site doping.
Moreover, a composition Pb0.97Nd0.02[(Zr0.3Ti0.4(Ni1/3Nb2/3)0.3)O3] is known from the publication of Schuh et al., Proc. Electroceramics V, Aveiro 1996 Vol. 1, 201. Furthermore, the incorporation of the compound Sr(K0.25Nb0.75)O3 in the perovskite lattice of PZT is described in the publication DE 198 40 488 A1.